Air It Out
A DIY fix for a leaky tender valve.
by Roger Hughes
Ihad never serviced the three air valves on my old 10-foot Caribe RIB dinghy since I bought it used, and it stayed suspended on davits on the stern of my schooner, Brittania, for months at a time. After all, I’m generally a firm believer in the old adage, “If it ain’t broke, don’t fix it.” But as with most old inflatables, it was necessary to reinflate it from time to time when it lost a little air. Lately, though, I had noticed the bow section needing more air than the other chambers; it was time to find out why.
The most obvious thing to look at first were the inflation/ deflation valves. There are three separate chambers in my dinghy, each served by a valve, called a Halkey Roberts air valve (halkeyroberts.com). These types of valves are also particularly commonly used on other inflatable brands.
I used the age-old soapywater testing method to find out if the valves leaked. I mixed a splash of dishwashing liquid in an old spray bottle and sprayed them. There they were: tiny bubbles emerging from around the outer ring of the bow chamber valve, indicating a definite leak. Surprisingly, no air was escaping from inside the valve itself.
Unfortunately, this meant the valve had to be removed for at least a cleaning, and more likely replacing. I hadn’t a clue how to do this, so I paid a visit to my local dinghy/life-raft repair shop to pick their brains. On seeing a new, complete valve, it was clear how it worked. It consists of a threaded holder inside the actual dinghy chamber, and an outer valve that screws tightly into the holder. An airtight seal is formed by tightening the two together and trapping the dinghy material between them. There is also a cap that locks on top of the valve to keep out water and debris. I also learned that I needed a special removal wrench to unscrew the two valve halves, which would be extremely tight, but one could easily be made from a short piece of ¾-inch plastic irrigation tube.
I left with a new valve, and made my own removal tool in five minutes in my garage by cutting a slot in one end of the irrigation tube and a hole in the other end to hold a screwdriver. The cutouts engage in the inside of the valve, which indeed proved to be exceedingly tightly screwed
together. I needed a long screwdriver for leverage to loosen the two halves. This is a normal right-handed thread and best started with the tube fully inflated, when it is more rigid. Once the valve came loose, I found that it could be unscrewed by hand. But this is where it got tricky.
The holder inside the dinghy is not physically attached to the inside of the tube, so before the valve is unscrewed completely, it is necessary to hold the inner half with one hand around the boat fabric to stop it from falling inside the tube. Once the valve was removed, I put a screwdriver through the holder to stop it from disappearing into the tube—or so I thought. As an aside, the inner valve holder cannot be pulled through the hole in the tube either. The hole is much too small, and the holders must have therefore been installed when the dinghy was built. This made me wonder why I needed to buy the inner holder at all, but that’s how they are sold.
On close inspection of the circular flange of the valve, it was obvious why it leaked. It was extremely dirty, with bits of grit most of the way around the seal. The circumference of the hole in the Hypalon tube material was also dirty. I used Zylene liquid to remove all the ingrained dirt from the valve.
The circumference of the hole in the tube itself was more difficult to clean. The screwdriver needed to be removed, and the loose holder held in place with one hand to stop it dropping into the tube, but naturally, the inevitable happened. The holder slipped out of my fingers and vanished inside the dark tube. After a lot of fiddling around, I managed to feel where it had fallen and waggle it back up to the hole, then lined it up to reinsert the new valve. It certainly would make things easier if dinghy-makers employing these types of valves could somehow attach the inner holder to the tube. However, I was told, under no circumstances to be tempted
Top to bottom: One of the trickiest parts of the whole operation is simply holding on; after unscrewing the outer valve, it’s difficult to hold the inner section to prevent it from slipping into the tube. But it is possible to use a screwdriver to support the inner holder while cleaning the valve. Once everything is screwed back together, a little batterypowered air compressor makes inflation simple. to use any sealant on either of the valve flanges. They need to be screwed together dry.
Once I managed to get them level, screwing the two together was quite easy, and I wound the new valve right into the holder until it was finger-tight. I then fully inflated the chamber using a small but powerful Porter Cable battery-powered compressor. I then tightened the two halves together as hard as I could, using my homemade wrench and screwdriver.
A water test proved I had solved the valve leak on the bow chamber, and apart from loosening the inner holder, it had all been fairly effortless. I therefore decided to ignore my old ain’t-broke adage and take apart the other two valves for inspection and cleaning. Indeed, they were both just as dirty, not only on the outer sealing ring, but also on two internal rubber O-rings. One was on the valve stem forming the actual air seal, and the other was on the cap. Both can be easily pried off and cleaned. On reassembly, I even managed to not let the inner holder fall into the tube again. These two valves should now be as efficient as the new one.
This was all quite a satisfying maintenance/repair exercise, and I am now a little bit more knowledgeable about another part of my cruising kit.